二次加砂压裂工艺研究与应用

华北油田油层杨氏模量低,岩石较软,油层上下没有理想的遮挡层,造成裂缝高度垂向延伸超出油层,支撑剂大部分填充在非目的层,同时支撑剂嵌入严重,降低了裂缝导流能力,导致了大量的无效井及低效井产生。在研究分析低效及无效原因的基础上,研究出二次加砂压裂工艺。此项技术是常规控制裂缝高度技术的发展,它通过改变岩石的力学状态、压裂液的流动路径,达到控制缝高的目的;通过增加支撑剂的铺置层数,扩展裂缝宽度,增加裂缝导流能力。此项技术现场应用40多井次,增加了压裂井的压后有效率及生产周期,取得了可观的经济效益及社会效益。

Research and Application on Second Sand Filling Fracturing

The formation of Huabei Oilfield has the character of low Yang's Modulus and soft rock. The formation doesn't possess the ideal barrier bed, which forms the fractures extend over the height of formation, so most parts of the proppants are filled in non-production formation, as well as serious proppant embedment. All of these decline the flow conductivity and come into many ineffective wells and low-effective wells. The article based on the research and analysis causing ineffective and low-effective, and conducted the process of second sand filling fracturing. This technology develops the normal fracture height controlling technology. Through changing the rock mechanics and the flow routine of fracturing fluids, it reached the purpose of controlling fracture height. Also through increasing the layer numbers of proppant filling, it extended the width of fractures and increased fracture flow conductivity. This technology has applied more than 40 wells onsite, it surely increased efficiency and production period after fracturing, and got valuable economic and social benefits.